The subject invention derives from the need to solve problems within the pharmaceutical industry relating to inaccurate or inconsistent dose division upon breaking of a dosage form. It is known that pharmaceutical tablets are commonly broken to modify the dose provided in a whole tablet. In the U.S., many “managed care” insurance organizations recommend or encourage patients to split or divide tablets, including unscored or irregularly-shaped tablets. These dosage adjustments, achieved through tablet breaking by patients, have been determined to be imprecise. Various solutions to these problems have been proposed but are of limited use, not being generally applicable to a wide variety of formulations.
Tablets are often produced with a score to aid breaking, but such tablet breaking is well-documented to suffer many problems whether or not scoring of the tablet is provided. Scored pharmaceutical tablets, layered or non-layered, fail to adequately address the problem because of uneven breaking, chipping, or crumbling that occurs upon breaking. Scores formed into a tablet have heretofore not exceeded 1 mm in depth.
In 1984, Stimpel, et al., found that tablet breaking was not accurate, even if performed by a sophisticated, dexterous person. M. Stimpel, et al., “Breaking Tablets in Half.” The Lancet (1984):1299.
In a report by Peek et al., “elderly patients” aged 50-79 using, without specific instruction, mechanical tablet splitters to break scored tablets produced highly unsatisfactory division of the tablets. Peek, B.T., Al-Achi, A., Coombs, S.J. “Accuracy of Tablet Splitting by Elderly Patients.” The Journal of the American Medical Association 288 No.4 (2002):139-145. Many drugs, such as warfarin, require dosage adjustments. Peek, et al. found warfarin 5 mg was, on average, split into 1.9 and 3.1 mg tablets when a mechanical tablet splitter was used. This potent anticoagulant has such a narrow therapeutic range that 2.0, 2.5, and 3 mg tablet doses are manufactured. Biron, et al., demonstrated that warfarin 10 mg also often split to less than 4.25 or greater than 5.75 mg. Biron, C., Liczner, P., Hansel, S., Schved, J. F., “Oral Anticoagulant Drugs: Do Not Cut Tablets in Quarters.” Thromb Haemost 1201 (1999). In addition, a statistically significant loss of mass resulted from crumbling or chipping when breaking the warfarin tablets.
Rodenhuis, et al., observed that, in 1998, European regulatory authorities started a policy to discourage scoring of tablets. N. Rodenhuis et al., “The rationale of scored tablets as dosage form.” European J. of Pharmaceutical Sciences 21 (2004):305-308. Rodenhuis, et al., attributed the new policy to reports of “bad functioning score lines,” “tablets difficult to break,” and “unsatisfactory mass uniformity of the subdivided halves.” Rodenhuis, et al. noted that “[i]mproving the functioning of score lines may be a more practical approach than banning this [scored] dosage form”.
US Application 2005/0019407A1 describes composite dosage forms having first and second portions joined at an interface. These dosage forms have a first molded material and a second compressed material. No disclosure is provided to teach or suggest any modification to facilitate the breaking or subdividing the dosage forms or providing a partial dose.
The present invention, as disclosed herein, can overcome or alleviate the problems discussed above, and can provide additional advantages and address other problems as would be well understood and recognized from this disclosure by persons of ordinary skill in this art.